1. Field of the Invention
The present invention relates to a method of automated optical inspection and an inspection device performing the same, more particularly to a method of bright spot defect detection for a polarizer and an inspection device performing the same.
2. Description of the Related Art
After a polarizer is manufactured, it is inspected using an automated optical inspection (AOI) system for detection of defects (e.g., bright spots). During the inspection, the AOI system captures an image of a target surface of the polarizer, analyzes the image thus captured using image processing techniques, and indicates any defect detected during the analysis for subsequent inspection by human inspectors.
However, the AOI system may be tricked by glares caused by a release film on the polarizer to indicate non-defective spots as being defective for subsequent human inspection, which renders the inspection process less efficient. Specifically, for each inspected pixel of the image captured by the AOI system, the AOI system is configured to determine if a brightness value of the pixel exceeds a threshold value, and to mark the corresponding spot on the polarizer for subsequent human inspection if affirmative. Accordingly, non-defective spots in regions of the target surface of the polarizer that correspond to extremely bright glares may thus have brightness values higher than the threshold value, and may thus be subjected to subsequent human inspection.